Ankle injuries to athletes and others that participate in physical activities are common and can be debilitating. The most common injuries to the ankle are to the ligaments. A ligament is made up of multiple strands of tissue, similar to a nylon rope. A sprain results in tearing of ligaments, the tear may be a complete tear of all the ligaments or a partial tear in which only a portion of the strands that make up the ligament are torn. The lateral ligaments of the ankle are by far the most commonly injured. It is estimated that lateral ligament sprains make up approximately 85% of all ankle sprains. Typically, the lateral ligaments are injured during an “inversion” injury to the ankle. An inversion injury occurs when the foot is rolled inwardly in an excessive manner thereby causing damage to the lateral ligaments. In addition to the discomfort and impairment in mobility caused by an ankle sprain, another problem caused by ankle sprains is the increased risk of re-injury. Once an ankle has been sprained, the stretching and tearing of the ligaments leads to instability in the ankle that commonly results in re-injury. It is estimated that spraining an ankle may increase the risk of re-injury by as much as 40-75%.
In view of the above, a wide variety of ankle supports and braces are currently available in a multitude of shapes, designs and materials which attempt to prevent ankle sprains and re-injury by providing additional lateral support to the ankle. Generally, prior art ankle supports fall within one of two broad categories which are discussed in further detail below.
One group of prior art ankle supports are “wrap” type supports. Such “wrap” type supports typically comprise a substantially flexible material that is tightly wrapped around the ankle to provide additional lateral support.
Normally, “wrap” type supports are applied in one of two ways. The first way is by applying a preparatory tape (i.e. “pre-wrap”) or partial sock to the ankle and then wrapping layers of athletic tape on top of the preparatory tape layer such that a plurality of overlapping layers are applied to the ankle. A shortcoming of this technique is that the application of such a support requires several layers of tape that must be applied by another person, such as a trained technician or doctor. Moreover, the application of the support can be time consuming. Another disadvantage of this technique is that if the plurality of tape layers are applied improperly, the taping may cause interference with proper blood circulation. Still another disadvantage with conventional ankle wrapping techniques is that the layers of tape cannot be applied in a uniform manner which results in irregularities in the degree of support, and the direction of support, provided at different locations in the support.
An example of a “wrap” type support is illustrated in U.S. Pat. No. 5,938,631 to Colman (hereinafter “the '631 patent”). The '631 patent purports to disclose a method for taping an ankle or joint. As shown in FIGS. 4 and 5 of the '631 patent, the ankle 26 and the forefoot area 24 is first wrapped with preparatory tape 22. A stirrup 28, made from a metal backed tape T is the applied over the sole 30. Thereafter, as shown in FIG. 5, the stirrup 28 is wrapped over with conventional adhesive tape.
The second type of ankle support found in the prior art are those braces that employ one or more rigid members that are secured to the ankle by a flexible strap, tape or the like. These “rigid” braces contain at least one rigid part constructed from a thermoplastic material, metal or some other rigid material. The rigid piece or pieces of the brace are normally arranged near the medial and lateral malleoli and serve to minimize the inversion and eversion movement of the ankle. A common shortcoming with “rigid” type braces is that they often experience slippage during use. Accordingly, the brace may cause chaffing of the skin and discomfort after extended use. Another disadvantage of “rigid” type braces is that they are often rather bulky and heavy. Still another disadvantage of a brace of this type is that they restrict the user's accessory range of motion, e.g. dorsiflexion and plantarflexion, thereby limiting optimal athletic performance. Yet another disadvantage of braces of this type it that they do not adhere to the skin. Therefore, they do not provide the necessary proprioceptive feedback to the user to limit the likelihood of injury to the ankle.
An example of a “rigid” type brace is illustrated in U.S. Pat. No. 6,056,713 to Hayashi (hereinafter “the '713 patent”). The '713 patent purports to disclose an ankle brace 10 having a thermoplastic sheet 11 which is heated and molded to the ankle of the user. A cushioning material 24 made of a resilient foam material is provided on an inner surface of the ankle brace 10. As seen in FIGS. 1 and 5 of the '713 patent, the ankle brace 10 is held in place around the ankle by a strap 28 of loop textured material (i.e. VECLRO) having a buckle 29 that wraps around an upper portion 20 of the thermoplastic sheet 11 and is fastened in place with a hook textured material pad 40. Ankle strap 32 holds the medial and lateral extensions 12 and 14 of the lower portion of the thermoplastic sheet 11 around the ankle.